dig
NetworkPackage: bind9-dnsutils
Queries the DNS and shows the raw answer, with the TTL and the server that answered. dig +short for the value; dig @1.1.1.1 to ask a specific resolver rather than the local cache.
What its options do in the lessons
From the same glossary the lessons render under their commands, so the two cannot disagree.
dig -x- Reverse lookup: asks for the name attached to an IP address.
dig -x 203.0.113.10builds thein-addr.arpaPTR query for you, which otherwise has to be written out backwards by hand.
Lessons that teach it
- Creating a site, then putting a Node.js application on itISPConfig: hosting several sites on one server
- Mailboxes and DNS zones from the panelISPConfig: hosting several sites on one server
- A query's path, and the propagation mythDNS: pointing a domain at your server
- Publishing the records, and verifying before you continueDNS: pointing a domain at your server
- What the application asks, and why dig answers a different questionDNS: pointing a domain at your server
- What a failed lookup tells you, and whose problem it isDNS: pointing a domain at your server
- Why fixing the typo does not help yetDNS: pointing a domain at your server
- Moving a live domain: the record change is the shortest partDNS: pointing a domain at your server
- The check that cannot fail, and the flush that proves nothingDiagnosing a failure: what each output proves
- From a symptom to one component: what the hypothesis forbidsDiagnosing a failure: what each output proves
- The order, and why it is that oneThe capstone: from repository to production